Boost leak test results q&a

[20Vcqdriver]

Ok did a boost leak test on the Cq yeterday and first try the oil dipstick flew out, secured and 2nd attempt I could hear a small amount of air escaping down the exhaust that I assume is where the air is passing the rings and escaping through the open exhaust valves, other than this no other signs of air escaping and it took almost 2 minutes before the air pressure had dropped from 2 to 1 bar
Is this an acceptable result or should I speed up the build of this spare block I'm working on?

[Jamo]

Dis you block of the pcv system before pressure testing?

[prj]

Probably not... block it off at the front.
Also block the hose going to the lower chamber of the wastegate while leak testing.

[20Vcqdriver]

Dis you block of the pcv system before pressure testing?

Only blocked the one that goes to the MAF to Turbo hose. Why do you need to block wastegate hose as should diaphram be perished, leak test to this too would show it up.

[prj]

WG will always leak into exhaust.
Diagram should be checked by visual inspection.

[Rusty]

Results sound pretty decent to me. If you had 2 bar in there and those were the only leaks, then you're lauging. Good idea to test the DV by blocking it up too; hadn't done that before.

[Fat Audi 80]

Yep, when S2Driver's car had a boost leak the air was coming out as fast the compressor could put it in!

[prj]

Per description everything is alright indeed.

[Rusty]

I need to get something that can give 2 bar of pressure into the system... a hand / foot pump just won't get enough air in

[20Vcqdriver]

I used a spare tyre inflated to 50psi that dropped to 30 (on boost gauge) once attached to the engine via an adapter I made..

[prj]

I used a spare tyre inflated to 50psi that dropped to 30 (on boost gauge) once attached to the engine via an adapter I made..

That's pretty clever.

[SteveH]

I need to get something that can give 2 bar of pressure into the system... a hand / foot pump just won't get enough air in

I have a compressor and leak testing bung. Call round if you want to use it.

[s2driveruk]

Yep, when S2Driver's car had a boost leak the air was coming out as fast the compressor could put it in!

yes, how my car ever made any boost on the RR day is beyond me with the trail of leaks...ended up being WGFV split, crack in the IM and a split in the plastic elbow pipe going into the MAF-Turbo hose.

[driftin jo]

I used a spare tyre inflated to 50psi that dropped to 30 (on boost gauge) once attached to the engine via an adapter I made..

That's what I use as well, I have a pressure bleeder for pressurising the brake fluid reservoir and I use the adaptor hose from this which connects to a valve on a spare tire.
It's the same thing as you have on a foot pump so you could use the hose from one of those also.

[Rusty]

Cheers Steve, I'll take you up on that Got a bung kit but not enough puff Need to test to 1.8 bar at least :mischeif: